freebsd-skq/sys/geom/geom_vfs.c
Alexander Motin e521fb0558 Partially revert r238886 in part of GEOM_VFS spoiling.
This change triggered interesting foot shooting condition in GEOM when
RW access to root partition by fsck spoils VFS geom there, which has it
opened RO at the same time.  Seems spoiling concept needs some rework.
2012-07-29 20:04:09 +00:00

292 lines
6.9 KiB
C

/*-
* Copyright (c) 2004 Poul-Henning Kamp
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/vnode.h>
#include <sys/mount.h> /* XXX Temporary for VFS_LOCK_GIANT */
#include <geom/geom.h>
#include <geom/geom_vfs.h>
/*
* subroutines for use by filesystems.
*
* XXX: should maybe live somewhere else ?
*/
#include <sys/buf.h>
struct g_vfs_softc {
struct mtx sc_mtx;
struct bufobj *sc_bo;
int sc_active;
int sc_orphaned;
};
static struct buf_ops __g_vfs_bufops = {
.bop_name = "GEOM_VFS",
.bop_write = bufwrite,
.bop_strategy = g_vfs_strategy,
.bop_sync = bufsync,
.bop_bdflush = bufbdflush
};
struct buf_ops *g_vfs_bufops = &__g_vfs_bufops;
static g_orphan_t g_vfs_orphan;
static struct g_class g_vfs_class = {
.name = "VFS",
.version = G_VERSION,
.orphan = g_vfs_orphan,
};
DECLARE_GEOM_CLASS(g_vfs_class, g_vfs);
static void
g_vfs_destroy(void *arg, int flags __unused)
{
struct g_consumer *cp;
g_topology_assert();
cp = arg;
if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
g_access(cp, -cp->acr, -cp->acw, -cp->ace);
g_detach(cp);
if (cp->geom->softc == NULL)
g_wither_geom(cp->geom, ENXIO);
}
static void
g_vfs_done(struct bio *bip)
{
struct g_consumer *cp;
struct g_vfs_softc *sc;
struct buf *bp;
int vfslocked, destroy;
struct mount *mp;
struct vnode *vp;
struct cdev *cdevp;
/*
* Collect statistics on synchronous and asynchronous read
* and write counts for disks that have associated filesystems.
* Since this run by the g_up thread it is single threaded and
* we do not need to use atomic increments on the counters.
*/
bp = bip->bio_caller2;
vp = bp->b_vp;
if (vp == NULL) {
mp = NULL;
} else {
/*
* If not a disk vnode, use its associated mount point
* otherwise use the mountpoint associated with the disk.
*/
VI_LOCK(vp);
if (vp->v_type != VCHR ||
(cdevp = vp->v_rdev) == NULL ||
cdevp->si_devsw == NULL ||
(cdevp->si_devsw->d_flags & D_DISK) == 0)
mp = vp->v_mount;
else
mp = cdevp->si_mountpt;
VI_UNLOCK(vp);
}
if (mp != NULL) {
if (bp->b_iocmd == BIO_WRITE) {
if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
mp->mnt_stat.f_asyncwrites++;
else
mp->mnt_stat.f_syncwrites++;
} else {
if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
mp->mnt_stat.f_asyncreads++;
else
mp->mnt_stat.f_syncreads++;
}
}
cp = bip->bio_from;
sc = cp->geom->softc;
if (bip->bio_error) {
printf("g_vfs_done():");
g_print_bio(bip);
printf("error = %d\n", bip->bio_error);
}
bp->b_error = bip->bio_error;
bp->b_ioflags = bip->bio_flags;
if (bip->bio_error)
bp->b_ioflags |= BIO_ERROR;
bp->b_resid = bp->b_bcount - bip->bio_completed;
g_destroy_bio(bip);
mtx_lock(&sc->sc_mtx);
destroy = ((--sc->sc_active) == 0 && sc->sc_orphaned);
mtx_unlock(&sc->sc_mtx);
if (destroy)
g_post_event(g_vfs_destroy, cp, M_WAITOK, NULL);
vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
bufdone(bp);
VFS_UNLOCK_GIANT(vfslocked);
}
void
g_vfs_strategy(struct bufobj *bo, struct buf *bp)
{
struct g_vfs_softc *sc;
struct g_consumer *cp;
struct bio *bip;
int vfslocked;
cp = bo->bo_private;
sc = cp->geom->softc;
/*
* If the provider has orphaned us, just return EXIO.
*/
mtx_lock(&sc->sc_mtx);
if (sc->sc_orphaned) {
mtx_unlock(&sc->sc_mtx);
bp->b_error = ENXIO;
bp->b_ioflags |= BIO_ERROR;
vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
bufdone(bp);
VFS_UNLOCK_GIANT(vfslocked);
return;
}
sc->sc_active++;
mtx_unlock(&sc->sc_mtx);
bip = g_alloc_bio();
bip->bio_cmd = bp->b_iocmd;
bip->bio_offset = bp->b_iooffset;
bip->bio_data = bp->b_data;
bip->bio_done = g_vfs_done;
bip->bio_caller2 = bp;
bip->bio_length = bp->b_bcount;
g_io_request(bip, cp);
}
static void
g_vfs_orphan(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_vfs_softc *sc;
int destroy;
g_topology_assert();
gp = cp->geom;
g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
sc = gp->softc;
if (sc == NULL)
return;
mtx_lock(&sc->sc_mtx);
sc->sc_orphaned = 1;
destroy = (sc->sc_active == 0);
mtx_unlock(&sc->sc_mtx);
if (destroy)
g_vfs_destroy(cp, 0);
/*
* Do not destroy the geom. Filesystem will do that during unmount.
*/
}
int
g_vfs_open(struct vnode *vp, struct g_consumer **cpp, const char *fsname, int wr)
{
struct g_geom *gp;
struct g_provider *pp;
struct g_consumer *cp;
struct g_vfs_softc *sc;
struct bufobj *bo;
int vfslocked;
int error;
g_topology_assert();
*cpp = NULL;
bo = &vp->v_bufobj;
if (bo->bo_private != vp)
return (EBUSY);
pp = g_dev_getprovider(vp->v_rdev);
if (pp == NULL)
return (ENOENT);
gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
mtx_init(&sc->sc_mtx, "g_vfs", NULL, MTX_DEF);
sc->sc_bo = bo;
gp->softc = sc;
cp = g_new_consumer(gp);
g_attach(cp, pp);
error = g_access(cp, 1, wr, wr);
if (error) {
g_wither_geom(gp, ENXIO);
return (error);
}
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vnode_create_vobject(vp, pp->mediasize, curthread);
VFS_UNLOCK_GIANT(vfslocked);
*cpp = cp;
cp->private = vp;
bo->bo_ops = g_vfs_bufops;
bo->bo_private = cp;
bo->bo_bsize = pp->sectorsize;
return (error);
}
void
g_vfs_close(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_vfs_softc *sc;
g_topology_assert();
gp = cp->geom;
sc = gp->softc;
bufobj_invalbuf(sc->sc_bo, V_SAVE, 0, 0);
sc->sc_bo->bo_private = cp->private;
gp->softc = NULL;
mtx_destroy(&sc->sc_mtx);
if (!sc->sc_orphaned || cp->provider == NULL)
g_wither_geom_close(gp, ENXIO);
g_free(sc);
}